The BFT-1B from One Electron was designed to power a stereo amplifier using UBT-1's in each channel but will also power an 80 watt push-pull tube amplifier. The BFT-1B is slightly larger than earlier versions of the BFT-1, allowing lower flux density and cooler operation. The tapped high-voltage windings and three filament windings provide flexibility in design. An electrostatic shield between the primaries and secondaries reduces power-line noise coupling. The primary arrangements allows use on virtually any power grid in the world.

The UBT-1 from One Electron is a low-impedance single-ended output transformer intended for parallel combinations of tubes running a B+ voltages of 250 to 325 volts, such as: two or three EL34s (triode connected), three 2A3s, two 300Bs, two 6AS7s, etc., as well as single sweep tubes run in 'enhanced-triode' mode, resulting in 10 to 15 watts of output power.

The UBT-2 from One Electron is the same size and power (15 watts) as the UBT-1, but has a higher primary impedance suitable for single tubes running at B+ voltages of 400 to 500 volts, such as: 50, WE 300B,etc.

The UBT-3 from One Electron is the same size and power (15 watts) as the UBT-1, but has a primary impedance suitable for single or paralleled tubes running at B+ voltages of 300 to 400 volts, such as: 2A3, WE 300B, 50, etc.